Effect of visual feedback and verbal encouragement on concentric quadriceps and hamstrings peak torque of males and females

How should we normalize electromyograms obtained from healthy participants? What we have learned from over 25years of research

“…Burnett et al (2007) noted that the reliability of EMGs from submaximal isometric contractions was improved by visual feedback. The generally positive effects of both verbal and visual feedback on the peak torque from MVCs have also been well documented, recently by Campenella et al (2000). Finally, the way in which MVCs are elicited has also been reported to influence both muscle activity and peak torque.…”

Reliability of electromyographic methods used for assessing hip and knee neuromuscular activity in females diagnosed with patellofemoral pain syndrome

“…A CV was calculated and another trial taken, if necessary, to ensure that subjects had three force measures with variability less than 10% (Agre et al, 1987). All subjects received strong verbal encouragement during testing (Campenella et al, 2000). The muscle testing order was randomized to account for ordering bias.…”

Reliability of electromyographic normalization methods for evaluating the hip musculature

“…Prior works have shown that use of straps can facilitate reliability for generating a MVIC [2,27,35,46]. We also gave strong verbal encouragement, a proven technique for eliciting a maximum contraction [12] and practice to familiarize themselves with the task. We believe that the combination of positioning, verbal encouragement, and task familiarization facilitated a subject's ability to perform a reliable MVIC as evidence by the calculated ICC of 0.92.…”

“…For testing purposes, subjects performed three MVICs using the ''make test'' and rested 1 min between each effort to minimize fatigue. The principal investigator provided strong verbal encouragement to facilitate subjects' ability to perform a MVIC [12]. To determine reference values for the mean and peak dynamic normalization methods, subjects performed 15 repetitions of active right hip abduction (0-25 degrees) in the sidelying position with no load (no ankle weight) at a rate of 60 beats per minute.…”